TL;DR Cisco fixed 18 Cisco Secure Firewall vulnerabilities on September 16, 2026. Several are critical and allow remote code execution as root. The flaws span Firewall Management Center, ASA, and Threat Defense software. Why these Cisco Secure Firewall vulnerabilities matter Firewalls guard the edge of nearly every enterprise network. A root compromise there breaks that first line of defense. These Cisco Secure Firewall vulnerabilities include several paths to full device takeover.